黄喉雉鹑高海拔适应的全基因组分子机制

Buff-throated partridge Tetraophasis szechenyii (Galliformes, Phasianidae) is endemic to western China, and is legally listed as a category I species of nationally protected animals in China. This species inhabits coniferous forests, alpine shrub lands, and tundra above 3500 m in elevation, which is a native bird to the Qinghai-Tibetan Plateau. Multiply adaptive evolutions were found in this bird, feathered tarsus, body shape, reproductive behavior and mitochondiral genes were adaption to cold climate and high-altitude. In this study, the whole genome of T. szechenyii will be de novo sequenced to investigate the molecular mechanisms of high-altitude adaptation in T. szechenyii. A comparative genomic analysis will be performed between high-altitude T. szechenyii and three low-altitude Galliformes birds, including Gallus gallus, Meleagris gallopavo and Arborophila rufipectus. And we will use the genomic data to detect possible convergent evolution between the no-passeriformes bird T. szechenyii and passeriformes bird Parus humilis in response to high-altitude stress. Our study will provided some clues that may be important for understanding high-altitude adaptations in Phasianidae, and convergent evolution studies have important significance for us to understand the molecular mechanism of high-altitude adaptation in Aves.

黄喉雉鹑Tetraophasis szechenyii是中国鸟类特有种，国家Ⅰ级重点保护野生动物。黄喉雉鹑分布于青藏高原东部边缘，栖息于3500米以上的高海拔地区，是青藏高原土著种，已在外形、体型、繁殖行为及线粒体基因方面对高海拔环境产生了适应。本研究对黄喉雉鹑基因组进行从头测序，得到黄喉雉鹑的参考基因组序列，通过与低海拔分布的鸡形目鸟类原鸡Gallus gallus、火鸡Meleagris gallopavo和四川山鹧鸪Arborophila rufipectus的基因组进行比较基因组分析，揭示黄喉雉鹑对青藏高原高海拔的适应机制，为雉科高海拔分布鸟类的研究起到奠基作用。同时，对高海拔分布的雀形目鸟类地山雀Parus humilis 和非雀形目鸟类黄喉雉鹑的基因组进行高海拔适应的趋同进化基因分析，以期全面揭示鸟类对高海拔的适应机制。

我国是雉科鸟类资源最丰富的国家。青藏高原分布有约20种雉科鸟类。本研究以黄喉雉鹑和血雉作为高海拔分布的代表物种，对黄喉雉鹑和血雉的基因组进行从头测序，通过与低海拔分布的鸡形目鸟类，如海南山鹧鸪、四川山鹧鸪的基因组等进行比较基因组分析，发现黄喉雉鹑中分布在HIF-1信号通路，对低氧的响应，对含氧化合物的响应，三磷酸腺苷结合和血管形成通路和高海拔适应相关的一些基因在黄喉雉鹑中受到了正选择作用，并且线粒体离子肽酶1(LONP1)中含有一个特有的氨基酸非同义突变，其与内固醇激素受体活性相关的基因发生了扩张，而与免疫和嗅觉相关的基因发生了收缩。血雉基因组中发现16个正选择基因都含有血雉特有的氨基酸非同义突变，其中一个特别重要的是正选择基因是肌红蛋白，该基因与高海拔适应性直接相关，并且含有2个血雉特有的氨基酸非同义突变（Leu41Gln和Met56Leu）。本研究揭示了以黄喉雉鹑为代表的雉科鸟类对青藏高原高海拔的适应机制，为雉科高海拔分布鸟类的研究起到奠基作用。